The Asian black bear (Ursus thibetanus) is also known as moon bear and white-chested bear. It is a medium-sized bear species and largely adapted to arboreal life. It is found in the Himalayas, in the northern parts of the Indian Subcontinent, Korea, northeastern China, the Russian far east, the Honshū and Shikoku islands of Japan, and Taiwan. It is classified as "Vulnerable" by the IUCN, mostly because of deforestation and hunting for its body parts.

The species is morphologically very similar to some prehistoric bears, and is thought by some scientists to be the ancestor of other extant bear species (aside from pandas and spectacled bears).Though largely herbivorous, Asian black bears can be very aggressive toward humans, who frequently trap or kill them for traditional medicine, and have frequently attacked people without first suffering what is generally considered to be sufficient provocation. The species was described by Rudyard Kipling as "the most bizarre of the ursine species."

Characteristics

The white V shaped chest mark of an Asian black bear

Asian black bears are black and have a light brown muzzle. They are white on the chin, and have a distinct white patch on the chest, which sometimes has the shape of a V. Their ears are bell shaped, proportionately longer than those of other bears, and stick out sideways from the head. The tail is 11 cm (4.3 in) long.[4] Adults measure 70–100 cm (28–39 in) at the shoulder, and 120–190 cm (47–75 in) in length. Adult males weigh 60–200 kg (130–440 lb) with an average weight of about 135 kg (298 lb). Adult females weigh 40–125 kg (88–276 lb), and large ones up to 140 kg (310 lb).

Asian black bears are similar in general appearance to brown bears, but are more lightly built and are more slender limbed. The lips and nose are larger and more mobile than those of brown bears. The skulls of Asian black bears are relatively small, but massive, particularly in the lower jaw. Adult males have skulls measuring 311.7 to 328 mm (12.27 to 12.91 in) in length and 199.5–228 mm (7.85–8.98 in) in width, while female skulls are 291.6–315 mm (11.48–12.40 in) long and 163–173 mm (6.4–6.8 in) wide. Compared to other bears of the genus Ursus, the projections of the skull are weakly developed; the sagittal crest is low and short, even in old specimens, and does not exceed more than 19–20% of the total length of the skull, unlike in brown bears, which have sagittal crests comprising up to 41% of the skull's length.

Although mostly herbivorous, the jaw structure of Asian black bears is not as specialised for plant eating as that of pandas: Asian black bears have much narrower zygomatic arches, and the weight ratio of the two pterygoid muscles is also much smaller in Asian black bears. The lateral slips of the temporal muscles are thicker and stronger in black bears.

A black bear with broken hind legs can still climb effectively. In contrast to polar bears, Asian black bears have powerful upper bodies for climbing trees, and relatively weak hind legs. which are shorter than those in brown bears and American black bears.They are the most bipedal of all bears, and have been known to walk upright for over a quarter mile.The heel pads on the forefeet are larger than those of most other bear species. Their claws, which are primarily used for climbing and digging, are slightly longer on the fore foot (30–45 mm) than the back (18–36 mm), and are larger and more hooked than those of the American black bear.

On average, adult Asian black bears are slightly smaller than American black bears, though large males can exceed the size of several other bear species.

The famed British sportsman known as the "Old Shekarry" wrote of how a black bear he shot in India probably weighed no less than 363 kg (800 lb) based on how many people it took to lift its body.The largest Asian black bear on record allegedly weighed 200 kg (440 lb).Zoo-kept specimens can weigh up to 225 kg (496 lb). Although their senses are more acute than those of brown bears, their eyesight is poor, and their powers of hearing moderate, the upper limit being 30 kHz.